Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 8,618	$ 8,199
Accumulated Amortization	(5,032)	(4,882)
Net Carrying Value	$ 3,586	$ 3,317
Weighted Average Useful Life	7 years 1 month 6 days	7 years 1 month 6 days
Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,900	$ 3,900
Accumulated Amortization	(3,900)	(3,900)
Net Carrying Value	0	0
Vision Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,929	2,929
Accumulated Amortization	(911)	(819)
Net Carrying Value	$ 2,018	$ 2,110
Weighted Average Useful Life	8 years	8 years
Software development in process costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,093	$ 674
Accumulated Amortization	0	0
Net Carrying Value	1,093	674
IntellitraffiQ Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	468	468
Accumulated Amortization	(88)	(59)
Net Carrying Value	$ 380	$ 409
Weighted Average Useful Life	4 years	4 years
Wrong Way Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 228	$ 228
Accumulated Amortization	(133)	(104)
Net Carrying Value	$ 95	$ 124
Weighted Average Useful Life	2 years	2 years